Blood flow measurement is vital to many research studies, and is best done with implanted sensors. This reduces the number of animals studied because implanted sensors lower measurement variability and improve accuracy. However, current flowmeter technology requires that the animals be hard-wired to the recording instrument. This puts the animal and the investment in surgical instrumentation at risk, and may alter flow due to the stressful experimental setting. Transonic Systems will resolve this problem by developing a miniaturized, battery powered wireless flowmeter. This device will drive surgically implanted flow probes and transmit realtime flow from free- roaming animals. It will be small enough to be implanted in larger animals or attached as a "backpack" to the rat. It will have the accuracy of current benchtop flowmeters and a battery life matched to typical chronic studies. The Phase-I research will demonstrate concept feasibility by integrating a commercial telemetry system with a miniaturized low-power flowmeter module implemented as a hybrid microcircuit, and will conduct bench and field studies to determine measurement accuracy. Subsequent Phase- II research will develop a custom integrated circuit chip-set that implements a complete flowmeter. During Phase-III commercialization we will make the chip-set available to all research instrumentation manufacturers. PROPOSED COMMERCIAL APPLICATIONS: A miniaturized, affordable flow module with telemetry has exciting commercial potential, since researchers could immediately apply it to chronic studies involving rats, primates, and pigs. Established biomedical equipment suppliers could integrate the flowmeter chip set with their other physiological sensors and their own telemetry systems. The same hardware could be adapted for medical uses such as flow measurement in Ventricular Assist Devices, and monitoring flow changes after cardiac bypass surgery.